/in/foo.c: In function 'main':
/in/foo.c:42:12: warning: zero-length gnu_printf format string [-Wformat-zero-length]
     printf("");
            ^~
/in/foo.c:44:14: warning: implicit declaration of function 'strlen' [-Wimplicit-function-declaration]
     if (text[strlen(text) - 1] == '\n') {
              ^~~~~~
/in/foo.c:44:14: warning: incompatible implicit declaration of built-in function 'strlen'
/in/foo.c:44:14: note: include '<string.h>' or provide a declaration of 'strlen'
/in/foo.c:48:12: warning: zero-length gnu_printf format string [-Wformat-zero-length]
     printf("");
            ^~
/in/foo.c:50:17: warning: incompatible implicit declaration of built-in function 'strlen'
     if (keyword[strlen(keyword) - 1] == '\n') {
                 ^~~~~~
/in/foo.c:50:17: note: include '<string.h>' or provide a declaration of 'strlen'